Work will continue on the purification and characterization of antigens from the soluble portion of the small particle fraction derived from the larva of Trichinella spiralis. The techniques of affinity chromatography, molecular sizing column chromatography, preparative isoelectric focusing in flatbed configuration, and the initiation of studies employing hybridoma technology will be employed for this purpose, Purified antigens will be characterized regarding their molecular weight, isoelectric point, carbohydrate contents, amino acid composition, amino acid sequence (when feasible), ability to induce protection against a challenge infection, location in the muscle larva (i.e. stichocyte granules or somatic tissues), and their relevance to the immunodiagnosis of trichinellosis in both the human and pig. TEM and SEM studies on the morphology of larval development, both in the enteral and parenteral phase, will continue as a collaborative effort, as well as work on observing in vivo, the penetration of muscle cells by the newborn larva.